Lesson 5: Rocks, Rocks, Rocks

Asteroid Impact Lesson 5: Rocks, Rocks, Rocks 1

What if your proposed locations are in bad rock formations? What if the caverns collapse? What if the rock is too hard to dig through? What if water flows right through the rock? These are important questions. Civil engineers and mining engineers deal with these questions all the time. Civil engineers design tunnels under cities, rivers and even oceans for cars and trains. Mining engineers design deep caverns – miles below the surface – for mining precious metals and diamonds. It’s critical to investigate and understand the properties of the rocks when designing a cavern or tunnel in that rock. Some rocks are like chalk – they crumble and snap. Other rocks are extremely hard. You can imagine that the strength of the cavern depends on the rock. Your engineering team should now begin to test the different rocks found in Alabraska to determine their properties. These rock properties will help you determine the best locations for your cavern(s).

Follow the rock testing procedure below and fill in the “Rock Test Data Table”. You will also need to use the “Rock Identification Flow Chart” to complete the table. After correctly identifying each rock, answer all the questions at the end of this worksheet.

Rock Testing 6. Record the luster. Is the rock dull or 1. Your teacherP wrilocedul provirede you with shiny? rocks. 7. Put a drop of vinegar on each rock. Record whether it fizzes or not, and Record the sample ID number in the then dry off each rock with a paper ID# towel. 2. coluUsingm nthe of Mtheohs table. Hardness Scale (on 8. Put each rock in a glass of water. the right), Does it float or sink? Dry off each rock after testing it. perform the hardness tests and record the hardness value in the hardness column of the Rock Test Data Table. 3. Record the brightness of each rock in the table. 4. Observe the particles of the rock sample. Can you actually see grains - like the sand on a beach? Record your answer in the granular column of the data table. 5. Observe the surface of the rock sample. Does it appear to have holes in it where water could penetrate, or is the surface more solid? Record your observations in the data table. 10. Use your textbook to classify 9. Follow the flow chart to identify the rock as igneous, sedimentary the name of each rock. or metamorphic.

Mohs Hardness Scale Asteroid Impact 2 1. If you hammered a nail into pumic, 4. How might the presence of pores or holes what would happen? Into granite? affect your cavern design? Which of the Explain. rocks are solid? (Use Rock ID chart).

2. How important is rock harness to designing and constructing caverns? What if rocks are too hard? What if rocks are too soft? 5. Is the color of the rock an important property for underground caverns? Explain.

3. Look at your rock test results and determine which rock is the hardest (not 6. Is the luster of the rock an important including diamond) and which is the softest. property for underground caverns? The hardest rock is Explain. and the softest rock is . Look on your geological map to see where these rocks are found in Alabraska. Identify them by the grid, using the nearest letter and number. The areas where the hardest rock is found are

The softest rock is found in what areas?